Consider the function $$f$$ defined by three plus the root of a given real number. Find its analytical expression as well as $$f (1), f (4)$$ and $$f^{-1}(7)$$.

See development and solution

### Development:

We write the algebraic expression of the function:

$$$f(x)=\sqrt{x}+3$$$

We can calculate now: $$$f(1)=\sqrt{1}+3=1+3=4$$$ $$$f(4)=\sqrt{4}+3=2+3=5$$$ $$$f^{-1}(7):$$$ $$$7=\sqrt{x}+3$$$ $$$4=\sqrt{x}$$$ $$$x=16$$$

### Solution:

$$f(x)=\sqrt{x}+3$$

$$f(1)=4$$

$$f(4)=5$$

$$f^{-1}(7)=16$$